Leonard: What were you doing at Penny's?
Sheldon: Well, we had dinner, played some games, and then I spent the night. Oh, and you'll be happy to know that I now have a much better understanding of 'friends with benefits.'

Sheldon: The correct animal for inter-species super soldier is the koala. You would wind up with an army so cute, it couldn't be attacked.

Penny: Look, can we just forget about this extra stuff and can you just tell me what Leonard does?
Sheldon: Alright. Leonard is attempting to learn why subatomic particles move the way they do.
Penny: Really? That's it? Well, that doesn't sound so complicated.
Sheldon: It's not. That's why Leonard does it.

Sheldon: I am not crazy, my mother had me tested.

Sheldon: This is the temperature you agreed to in the roommate agreement.
Leonard: Aw, screw the roommate agreement!
Sheldon: No, you don't screw the roommate agreement. The roommate agreement screws you.

Sheldon: You did this, didn't you?
Wil Wheaton: Come on, Sheldon, do you really think I'd break up a couple just to win a bowling game?
Sheldon: No, I suppose not.
Wil Wheaton: Good. Keep thinking that.
Sheldon: Wheeeeatoooon!

Sheldon: Amy, if you want to be my girlfriend again, I really want to be your boyfriend.
Amy: I really want that, too.
Sheldon: Good, because I love you.
Amy: I love you, too.
Dave: Kiss her, you brilliant fool!
(Sheldon kisses Amy)
Sheldon: Well, I'll let you get back to your date.

Sheldon: And just remember, I am proud of you and I support you in all that you do.
Amy: Thank you. That means a lot.
Sheldon: Oh, and one last thing. If you find yourself working with a male scientist who's as smart as me, as tall as me and has hair like Thor, well, then I want you to step away from the situation and call me immediately.

Sheldon: Are you sure? I've heard that on those sites, often when you think you're corresponding with someone, it's actually a computer program pretending to be a real person.
Raj: And you're afraid it'll do a better job than you?
Sheldon: Excuse me. No one does a better job pretending to be a person than I do. Siri comes close, but I know more jokes.

Sheldon: You may not realize it, but I have difficulty navigating certain aspects of daily life. You know, understanding sarcasm, feigning interest in others, not talking about trains as much as I want. It's exhausting!

Sheldon: Oh, I don't mind, I'm very good at complaining. If it were an Olympic sport, I'd complain about what a stupid sport it is and then I'd take home the gold.

Leonard: If you're worried, we can go over there and see if she's all right.
Sheldon: Okay. You know, I heard in the news a bobcat has been spotted in her neighborhood.
Leonard: I don't think Amy was eaten by a bobcat.
Sheldon: Who thinks Amy was eaten by a bobcat?
Leonard: You do?
Sheldon: Leonard, I was just mentioning an interesting local news item. Now, thanks to you, I'm worried Amy's been eaten by a bobcat.

Penny: Hey, I don't think she's wrong about you going too slow in the relationship.
Sheldon: Too slow?
Penny: Yeah, you've been going out for years. You haven't even slept together.
Sheldon: That's right. It's called foreplay.

Rajesh: Why so glum, chum?
Sheldon: Apparently you can't hack into a government supercomputer and then try to buy uranium without the Department of Homeland Security tattling to your mother.

Penny: I give up. He's impossible.
Sheldon: I can't be impossible; I exist. I think what you meant to say is, 'I give up; he's improbable'.